---
id: "CVE-2026-120236"
kind: "vulnerability"
aliases: ["CVE-2026-120236"]
title: "ag-ui protocol: improper input validation in transport decoder handler"
severity: "medium"
cvss: 6.5
epss: null
exploited: false
status: "open"
category: "ai-tooling"
products: []
ecosystems: []
tags: ["ag-ui", "ai-agents", "ai-tooling", "python", "typescript"]
not_affected_if: ["ag-ui-not-used"]
published_at: "2026-11-01T17:16:33+00:00"
first_seen_at: "2026-11-01T17:21:03+00:00"
updated_at: "2026-11-01T17:22:58+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-120236", "first_seen_at": "2026-11-01T17:21:03+00:00"}]
---

# ag-ui protocol: improper input validation in transport decoder handler

The ag-ui-protocol ag-ui package up to version 0.0.58 fails to validate input in its transport decoder handler. A remote attacker can send crafted data to trigger the flaw, and a public exploit exists.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed ag-ui-protocol version, for example with `pip show ag-ui-protocol` or `npm ls @ag-ui/core`, and compare it to `0.0.58`

## Fix

- Upgrade the affected ag-ui component past `0.0.58`; the source references patch commit 660182b973a44b8eda5484b14b88eb9cc251edc4 but does not name a fixed release version

## Timeline

- 2026-11-01T17:21:03+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-120236

## From the sources

A vulnerability was detected in ag-ui-protocol ag-ui up to 0.0.58. Affected by this vulnerability is an unknown functionality of the component Transport Decoder Handler. The manipulation results in improper input validation. The attack may be launched remotely. The exploit is now public and may be used. The patch is identified as 660182b973a44b8eda5484b14b88eb9cc251edc4. It is suggested to upgrade the affected component.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_